37.3k views
3 votes
A bag contains only red and blue marbles. Yasmine takes one marble at random from the bag. The probability that she takes a red marble is 1 in 5. Yasmine returns the marble to the bag and adds five more red marbles to the bag. The probability that she takes one red marble at random is now 1 in 3. How many red marbles were originally in the bag?

User Aubrey
by
8.9k points

1 Answer

6 votes
Answer: 5 Red Marbles

The bag started with 5 Red Marbles and 20 Blue Marbles

When you add the 5 additional red marbles it becomes 10 red marbles out of 30 total marbles or 1 in 3.
User Dotz
by
8.3k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories